150–200 mm Schmidt-Cassegrain on a GoTo alt-az
Celestron NexStar 5SE
Serious aperture in a tube half a metre long, on a computerised fork. The most capability per unit of storage space, at a price.
€889seen 7 Oct 2026 at Astroshop
- 125 mmAperture
- f/10.0Focal ratio
- 12 kgTypical weight
- 21–250×Useful magnification
Should you buy it?
- Yes if what you mainly want is the moon and the planets, nebulae, clusters and galaxies, by eye: that is what this family does best.
- No if your priority is taking it with me: other families do better for the same money.
Computed from its family's per-goal scores and its own numbers — not a rating, not one evening's opinion.
Where to buy
Also search at First Light Optics · Optique Unterlinden · Pierro Astro · Teleskop-Express (searches; neither price nor stock checked)
1 of these 5 links earn us a commission, marked above. Sorted by price, never by what pays. How this site is funded.
Prices are observed on the date shown, never live. Links marked paid link earn us a commission and cost you nothing extra.
What it shows, really
These circles are simulations, computed from the aperture, the magnification and the sky — indicative, not exact. A real night also depends on the turbulence, your eyes and your experience. Closer to the truth than the photo on the box; still not a promise.
Under a suburban sky (Bortle 6), through a common 25 mm eyepiece for wide targets and a 10 mm for planets. Every circle is the true field — nothing is enlarged.
Photo credits
These thumbnails are built from real photographs, scaled and darkened by the same arithmetic as the large view.
The numbers
Photo: Astroshop| Aperture | 125 mm |
|---|---|
| Focal ratio | 1250 mm · f/10.0 |
| Mount | Single-arm fork, GoTo alt-az |
| Typical weight | 12 kg |
| Eyepieces | 25 mm |
| Useful magnification | 21× to 250× at 125 mm |
| Resolution (Dawes) | 0.9″ — the tightest double star this aperture can split |
| Faintest star, suburban sky | around magnitude 11.8 |
| Observed price | €889 seen 7 Oct 2026 at Astroshop |
Made for
- The Moon and the planets
Aperture, focal length and tracking together — the combination high-power planetary work wants.
- Nebulae, clusters and galaxies, by eye
Real aperture, though the field is narrow and f/10 makes extended nebulae hard work.
- The Sun
In white light: sunspots with their penumbra, faculae near the edge, and granulation on a steady morning. Dawes' limit on the Sun: 0.9″ (116 ÷ 125 mm, arithmetic). It needs a certified cell over the front whose range holds its 152 mm outside diameter: the Omegon Helievo 152 (144–168 mm), €89 (seen 26 Sept 2026). Every time: certified filter over the front · finder capped · never an eyepiece filter · an adult with children · never without the filter · measure first.
Not made for
- Taking it with me
Compact for its aperture, but it is still a two-case operation.
The Sun, safely
No solar filter in the box
The Sun with this model
It needs a certified cell over the front whose range holds its 152 mm outside diameter: the Omegon Helievo 152 (144–168 mm), €89 (seen 26 Sept 2026).
In white light: sunspots with their penumbra, faculae near the edge, and granulation on a steady morning. Dawes' limit on the Sun: 0.9″ (116 ÷ 125 mm, arithmetic).
The listing gives a fit of 144–168 mm across the outside of the tube. Clear aperture 152 mm. The listing names no standard; no international standard exists for filters on telescopes, binoculars or lenses (AAS).
Where to buy
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Every time
- A certified solar filter over the FRONT of the instrument, fastened so it cannot slip or blow off.
- Cap or remove the finder. It is a second telescope, and it has no filter.
- Never a filter at the eyepiece end: the concentrated sunlight there can crack it in an instant.
- With children, an adult is there every time.
- Never look, or point, without the filter on. Check it before each use; a scratched or torn filter goes in the bin.
- Measure before ordering. A cell that sits loose can fall off.
Sources for the Sun
- American Astronomical Society — How to View a Solar Eclipse Safely — filters on optics go on the front; eclipse glasses never with optics; children supervised
- American Astronomical Society — Solar Filters for Optics — eyepiece filters are dangerous; the finder capped, removed or filtered; the filter attached securely
- American Astronomical Society — About the ISO 12312-2 Standard — EN ISO 12312-2:2015 covers naked-eye viewers only; no international standard covers filters on telescopes, binoculars or lenses
- Société astronomique de France — Guide des observations solaires — a filter at the front, never one screwed into the eyepiece, the finder capped
- NASA — Keep Your Eclipse Glasses to See the Sun's ‘Freckles’ — a large enough sunspot shows through eclipse glasses
- AAVSO — Le Guide d'Observation Solaire de l'AAVSO, v1.1 (2017), p. 6 — archived copy — “Les ouvertures plus grandes que 100 à 125 mm sont généralement limitées par les effets de turbulence atmosphérique”; 50 to 80 mm is enough to count sunspots
The family it belongs to: 150–200 mm Schmidt-Cassegrain on a GoTo alt-az
What it does well
- 200 mm of aperture in something one person can carry in two pieces
- GoTo plus tracking, which matters at high power and matters more when sharing a view
- Adapts to almost anything — imaging, planetary video, visual
What it costs you
- A 200 mm Dobsonian costs a third as much and shows the same amount
- Long cooling time and a narrow field
- Batteries, hand controllers and alignment stars, every single night
Worth knowing about this model
125 mm rather than the 150 mm this class starts at, and priced as though it were larger. Listed because it is the one people ask about.
Everything about 150–200 mm Schmidt-Cassegrain on a GoTo alt-az →
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€889seen 7 Oct 2026 at Astroshop
Where to buy